using Cinemachine;
using System;
using System.Runtime.CompilerServices;
using UnityEngine;

namespace TweenAnimation
{
    public enum ETweenType
    {
        Once,
        Looped,
        PingPong
    }

    [RequireComponent(typeof(CinemachineSmoothPath)), ExecuteAlways]
    public class TweenPath : MonoBehaviour
    {
        [Serializable]
        public class TweenTarget
        {
            public Transform transform;
            public float startPos;
        }

        [SerializeReference]
        public TweenTarget[] targets;

        [SerializeField]
        public CinemachineSmoothPath path;

        [SerializeField, HideInInspector]
        private Transform minStarPosTransform;

        [SerializeField]
        public ETweenType TweenType;

        [Min(0.1f)] public float Duration = 1;
        [Min(0)] public float Delay = 0;
        [SerializeField]
        public AnimationCurve speedCurve = AnimationCurve.Linear(0, 0, 1, 1);

        private float playTime = 0;
        private bool isPlaying = false;

#if UNITY_EDITOR
        public bool isEditing = false;
#endif

        private void Awake()
        {
#if UNITY_EDITOR
            path ??= GetComponent<CinemachineSmoothPath>();
#endif
        }

        private void Start()
        {
#if UNITY_EDITOR
            if (!Application.isPlaying)
            {
                return;
            }
#endif
            Play();
        }

#if UNITY_EDITOR
        [ContextMenu("Play")]
#endif
        public void Play()
        {
            isPlaying = true;
            playTime = 0;
        }

#if UNITY_EDITOR
        [ContextMenu("Stop")]
#endif
        public void Stop()
        {
            isPlaying = false;
            playTime = 0;
        }

        private void Update()
        {
#if UNITY_EDITOR
            if (targets == null)
            {
                return;
            }
            if (!isEditing && !isPlaying && !Application.isPlaying)
            {
                float minStartPos = 10;
                for (int i = 0; i < targets.Length; i++)
                {
                    var target = targets[i];
                    EvaluatePosition(target.transform, target.startPos);
                    if (target.startPos < minStartPos)
                    {
                        minStartPos = target.startPos;
                        minStarPosTransform = target.transform;
                    }
                }
            }
#endif
            if (!isPlaying)
            {
                return;
            }

            playTime += Time.smoothDeltaTime;
            if (playTime < Delay)
            {
                return;
            }
            for (int i = 0; i < targets.Length; i++)
            {
                var target = targets[i];
                var t = (playTime - Delay) / Duration + target.startPos;
                EvaluatePosition(target.transform, t);

                if (target.transform == minStarPosTransform && TweenType == ETweenType.Once && t >= 1)
                {
                    Stop();
                }
            }

        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void EvaluatePosition(Transform transform, float t)
        {
            if (TweenType == ETweenType.Looped)
            {
                t = t % 1.0f;
            }
            else if (TweenType == ETweenType.PingPong)
            {
                if (((int)t & 1) == 0)
                {
                    t = t % 1.0f;
                }
                else
                {
                    t = 1f - (t % 1.0f);
                }
            }

            var p = speedCurve.Evaluate(t);

            p = p * (path.MaxPos - path.MinPos);

            transform.localPosition = path.EvaluateLocalPosition(p);
        }
    }
}